4. Using the same muscular force, a karate chop with the side of the hand will hurt more than a hit with the open hand because:A the contact surface area is smaller with the karate blowB the karate fighter is small but hits harderC there are more bones in the side of the hand than the open hand

5. Four-wheel drive owners let air out of their tyres before driving on sand. This is because:A the tyre pressure increases when driving on sand compared with bitumen, and they are avoiding a blow-outB sand has more friction than bitumenC the contact area between the tyres and the sand is increased

6. A thumb tack has a large flat surface and a pointed end. With the same applied pressure, which part will have the greatest pressure?A the pointed endB the large flat part where the finger pushesC they have the same pressure

7. What happens to the water as one goes deeper into the ocean?A decreasesB stays the sameC increases

8. Ships are made from iron. The reason why they do not sink is because:A iron has a density less than waterB they have a large surface area of the hullC they are filled with air

9. Air pressure is less than that of liquids. This is because:Agases exert no pressure at allBair is less dense and takes up a greater volume and areaCliquids are less buoyant fluids than are gases

10. Atmospheric pressure at sea level is greater than on top of mountains. This is because: Athere is more air in a given area at sea level Bthere is less at sea level due to sea breezes Cwater eveporates to a vapour increasing the density of the air at sea level

11. Water boils on Mount Everest at a temperature less than 100 degrees Celsius. This is because: AMount Everest is always cold therefore all reactions occur at lower temperatures Bthere is less atmospheric pressure preventing the escape of gas bubbles from the water Cwater always boils at the same temperature no matter where it is on earth

12. The force of an object is 100 Newtons. The area on which the force acts is 2 square metres. What is the pressure in Newtons per square metre? A200 B100 C50

13. Two identical blocks of wood are placed side by side on a table. One lies on its larger side, and the other stands on its smaller end. Which is exerting the greatest pressure on the table? Athe one standing on its end Bthe one lying on the larger side Cboth exert the same pressure

15. A person whose mass is 50 kg (weight about 500 N) has a surface area on one foot of 0.01 square metres. What pressure does the person exert on the ground if standing on both legs? A50000 Newtons per square metre B25000 Newtons per square metre C5 Newtons per square centimetre